The recent expansion of gambling opportunities in the U.S. has been intended for adults, yet gambling extends to young people. In fact, existing research shows that adolescents and young adults are more likely to be classified as problem gamblers than older adults. Gambling among young people is also linked with substance use and delinquency. In spite of the increasing concern about youthful gambling, there have been no large representative U.S. studies of gambling and related behaviors among youth. The present study will be among the first. Our aims are: 1) to determine the prevalence and demographic patterns of gambling behaviors and pathological gambling among U.S. youth, 2) to examine the relationship of youth gambling to social and ecological factors such as neighborhood disadvantage, permissiveness of gambling laws, availability of gambling modalities, and the influence of peer gambling, 3) to examine the relationship between youth gambling and alcohol, tobacco and marijuana use, as well as conduct disorder and risky sexual behavior. We will conduct a computer-assisted telephone survey to interview 2500 U.S. residents aged 14 to 21. We will use a sample of phone numbers which is carefully stratified geographically to represent every area of the country. When contacting a household that contains more than one person aged 14-21, we will select the respondent at random. Tract-level and block-level census data will be used to characterize each respondent's neighborhood. A state-level data set will characterize the permissiveness of each state's gambling laws. Data analyses will examine the demographic and regional patterns of gambling behavior and pathology among U.S. youth. Further analyses will predict gambling behavior and pathology from geographic variables including permissiveness of state gambling laws and neighborhood social disadvantage, and examine the co-morbidity between pathological gambling and substance abuse as well as conduct disorder.